Effect of Pulsed TIG Welding Parameters on the Microstructure and Micro-Hardness of AA6061 Joints
- *Corresponding Author:
- Chennaiah MB
V.R Siddhartha Engineering College
Vijayawada, Andhra Pradesh, India
Tel: 91 9059041987
E-mail: [email protected]
Received Date: July 04, 2015; Accepted Date: July 14, 2015; Published Date: July 24, 2015
Citation: Chennaiah MB, Kumar PN, Rao KP (2015) Effect of Pulsed TIG Welding Parameters on the Microstructure and Micro-Hardness of AA6061 Joints. J Material Sci Eng 4: 182. doi:10.4172/2169-0022.1000182
Copyright: © 2015 Chennaiah MB, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Tungsten Inert Gas (TIG) welding process is generally used for welding of aluminum alloys. TIG process is generally preferred because it produces a very high quality weld. Distortion is the major problem in welding of thin sections. This distortion is controlled in pulsed and magnetic arc oscillation TIG process. The metallurgical advantages of pulsed TIG welding are grain refinement in fusion zone, reduced width of HAZ, less distortion, control of segregation, reduced hot sensitivity and residual stresses. It was observed that pulsed TIG welding produces finer grain structure of weld metal than conventional TIG welding (without arc pulsation). The mechanical properties (Hardness) and microstructure characteristic of weld metal depends upon the microstructure of the weld. The microstructure of the weld depends upon pulsed parameters peck current, base current, pulse frequency, pulse duration. The objective of present project is to achieve better mechanical properties. So, controlling of pulsed parameter is needed in this investigation. An increase in the pulse frequency has been found to refine the grain structure of weld metal especially when welding is done using short pulse duration. Long pulse duration lowers the pulse frequency up to which refinement of constituents in weld metal takes place. Effect of the pulse frequency on the grain structure was found to be determined by pulse duration. For a given pulse frequency, long pulse duration produced a coarser structure than short pulse duration. An increase in the peak current coarsened the grain structure.